Water-dilutable binders, aqueous paints containing these binders, and process for priming or painting plastics materials with a single coat of paint

ABSTRACT

The invention relates to water-dilutable binders which can be prepared by subjecting 
     (A) from 20 to 90% by weight of a mixture of 
     (a1) from 3 to 50% by weight of acrylic acid, methacrylic acid or of a mixture of acrylic acid and methacrylic acid, and 
     (a2) from 50 to 97% by weight of an ethylenically unsaturated monomer or of a mixture of ethylenically unsaturated monomers 
     to free-radical polymerization in the presence of 
     (B) from 9.9 to 79.9% by weight of a halogen-free copolymer composed of 
     (b1) from 1 to 99, preferably from 50 to 90% by weight, of propylene, 
     (b2) from 1 to 99, preferably from 10 to 50% by weight, of at least one olefin which is copolymerizable with (b1) and contains per molecule from five to twenty, preferably from six to eight, carbon atoms, with the exception of isoprene, and 
     (b3) from 0 to 50, preferably from 0 to 25% by weight, of ethylene and/or butylene, 
     or of a mixture of such copolymers, and 
     (C) from 0.1 to 10% by weight of a free-radical initiator or of a mixture of free-radical initiators, 
     and, after neutralization of at least 20% of the carboxyl groups which are present in the resulting polymerization product, dispersing the polymerization product in water, the sum of the percentages by weight of components (A), (B) and (C) and of (a1) and (a2) being in each case always 100% by weight, and the composition of the mixture of (al) and (a2) being selected such that polymerization of the mixture of (al) and (a2) alone gives a polymer which 
     has a glass transition temperature of from 0 to 150° C., and 
     contains from 0.04 to 1.0 milliequivalent of one or more of the following functional groups: —COOH, —OH, —NR3, —CN, —CONH2, —CO—, —NHCONH—, —OCONH—, —OP3H, —OSO3H, —R—O—R—, where R is an organic radical.

BACKGROUND OF THE INVENTION

The invention relates to water-dilutable binders, to aqueous coatingmaterials containing these binders and to processes for the priming orone-coat painting of plastics.

In order when painting plastics to achieve satisfactory adhesion of theapplied coat or the applied coats it is necessary to pretreat theplastic surface, for example by flame treatment, corona treatment,plasma treatment or by etching with chromosulfuric acid and/or primingwith special coating materials.

Pretreatment methods such as flame treatment, corona treatment, plasmatreatment or etching with chromosulfuric acid are associated withtechnical effort and/or should be avoided on ecological grounds.

To prime plastics based on polypropylene, it is usual to employ coatingmaterials which have the disadvantage that they includehalogen-containing binders (cf. for example JP-A-256 556/1989).

EP-A-468 644 describes coating materials which are said to be alsosuitable for the priming of plastics. The preparation of the bindersemployed in these coating materials, however, requires monomers whichcan be obtained only with difficulty.

The technical object of the present invention is to providewater-dilutable binders and aqueous coating materials which containthese binders and which can be employed in processes for the priming orone-coat painting of plastics.

SUMMARY OF THE INVENTION

This object is surprisingly achieved by the provision of water-dilutablebinders which are characterized in that they can be prepared bysubjecting

(A) from 20 to 90% by weight, preferably from 55 to 85% by weight, of amixture of

(a1) from 3 to 50% by weight, preferably from 5 to 15% by weight, ofacrylic acid, methacrylic acid or a mixture of acrylic acid andmethacrylic acid, and

(a2) from 50 to 97% by weight, preferably from 85 to 95% by weight, ofan ethylenically unsaturated monomer which is different from (a1) or ofa mixture of such ethylenically unsaturated monomers

to free-radical polymerization in the presence of

(B) from 9.9 to 79.9% by weight, preferably from 15 to 45% by weight, ofa halogen-free copolymer composed of

(b1) from 1 to 99, preferably from 50 to 90% by weight, of propylene,

(b2) from 1 to 99, preferably from 10 to 50% by weight, of at least oneolefin which is copolymerizable with (b1) and contains per molecule fromfive to twenty, preferably from six to eight, carbon atoms, with theexception of isoprene, and

(b3) from 0 to 50, preferably from 0 to 25%. by weight, of ethyleneand/or butylene,

or of a mixture of such copolymers, and

(C) from 0.1 to 10% by weight, preferably from 1 to 7% by weight, of afree-radical initiator or of a mixture of free-radical initiators,

and, after neutralization of at least 20% of the carboxyl groups whichare present in the resulting polymerization product, dispersing thepolymerization product in water, the sum of the percentages by weight ofcomponents (A), (B) and (C) and of (a1) and (a2) and (b1), (b2) and (b3)being in each case always 100% by weight, and the composition of themixture of (a1) and (a2) being selected such that polymerization of themixture of (a1) and (a2) alone gives a polymer which

has a glass transition temperature of from 0 to 150° C., preferably from10 to 80° C.,

contains from 0.04 to 1.0, preferably from 0.1 to 0.5 milliequivalent ofone or more of the following functional groups: —COOH, —OH NR₃, —CN,CONH₂, —CO—, —NHCONH—, —OCONH—, —OPO₃H, —OSO₃H, —R—O—R—, preferably—COOH, —CN, —CNH₂ and —R—O—R, where R is an organic radical, preferablyan alkyl or alkylene radical having 1 to 6 carbon atoms, and

which comprises from 0 to 50, preferably from 5 to 25% by weight of oneor more of the following cycloaliphatic groups which can be substitutedby at least one alkyl group which contains 1 to 12, preferably 1 to 6carbon atoms: cyclopentyl, cyclohexyl, perhydronaphthyl,perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl,bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl,bicycloundecyl and bicyclododecyl group, preferably cyclohexyl andisobornyl group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Aqueous coating materials containing these binders can be employed inprocesses for the priming or one-coat painting of plastics, especiallyplastics based on polypropylene and/or copolymers of propylene andcopolymerizable monomers, for example ethylene, and are notable for thefact that they give coating films which adhere very well to pretreatedand nonpretreated plastics substrates.

The mixture (A) employed to prepare the novel water-dilutable bindersconsists of

(a1) from 3 to 50% by weight, preferably from 5 to 15% by weight, ofacrylic acid, methacrylic acid or of a mixture of acrylic acid andmethacrylic acid, and

(a2) from 50 to 97% by weight, preferably from 85 to 95% by weight, ofan ethylenically unsaturated monomer or of a mixture of ethylenicallyunsaturated monomers,

the sum of the percentages by weight of components (a1) and (a2) beingalways 100% by weight, and the composition of the mixture of (a1) and(a2) being selected such that polymerization of the mixture of (a1) and(a2) alone gives a polymer which

has a glass transition temperature of from 0 to 150, preferably from 10to 80° C.,

contains from 0.04 to 1.0, preferably from 0.1 to 0.5 milliequivalent ofone or more of the following functional groups: —COOH, —OH, NR₃, CONH₂,—CO—, —NHCONH—, —OCONH—, OPO₃H, OSO₃H, —R—O—R—, preferably —COOH, —CN,—CHH₂ and —R—O—R—, where R is an organic radical, preferably an alkyl oralkylene radical having 1 to 6 carbon atoms, and

which comprises from 0 to 50, preferably from 5 to 25% by weight of oneor more of the following cycloaliphatic groups which can be substitutedby at least one alkyl group which contains 1 to 12, preferably 1 to 6carbon atoms: cyclopentyl, cyclohexyl, perhydronaphthyl,perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl,bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl,bicycloundecyl and bicyclododecyl group, preferably cyclohexyl andisobornyl group.

Since the glass transition temperatures of polymers prepared fromethylenically unsaturated monomers can be calculated in accordance withthe equation

1/Tg×ΣW _(n) /Tg _(n)

Tg=Glass transition temperature of the copolymer in ° K

W_(n)=Proportion by weight of the nth monomer

Tgn=Glass transition temperature of the homopolymer of the nth monomer,

and since ethylenically unsaturated monomers which contain —COOH, —OH,NR₃, —CN, CONH₂, —CO—, —NHCONH—, —OCONH—, OPO₃H, OSO₃H, —R—O—R—(where Ris an organic radical, preferably an alkyl or alkylene radical having 1to 6 carbon atoms), cyclopentyl, cyclohexyl, perhydronaphthyl,perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl,bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl,bicycloundecyl or bicyclododecyl groups are available commercially, theperson skilled in the art is able without difficulty to select thecomposition of the mixture of components (a1) and (a2) such that apolymer resulting from the polymerization of the mixture of (a1) and(a2) alone

has a glass transition temperature of from 0 to 150° C., preferably from10 to 80° C.,

contains from 0.04 to 1.0, preferably from 0.1 to 0.5 milliequivalent ofone or more of the following functional groups: —COOH, —OH—, NR₃, —CN,CONH₂, —CO—, —NHCONH—, —OCONH—, OPO₃H, OSO₃H, —R—O—R—preferably —COOH,—CN, —CNH₂ and —R—O—R—, where R is an organic radical, preferably analkyl or alkylene radical having 1 to 6 carbon atoms, and

which comprises from 0 to 50, preferably from 5 to 25% by weight of oneor more of the following cycloaliphatic groups which can be substitutedby at least one alkyl group which contains 1 to 12, preferably 1 to 6carbon atoms: cyclopentyl, cyclohexyl, perhydronaphthyl,perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl,bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl,bicycloundecyl and bicyclododecyl group, preferably cyclohexyl andisobornyl group.

Taking into account the selection criteria described above, possibleexamples for use as component (a2) are: esters of acrylic acid ormethacrylic acid, especially aliphatic and cycloaliphatic acrylates ormethacrylates having up to 20 carbon atoms in the alcohol radical, forexample methyl, ethyl, propyl, butyl, hexyl, ethylhexyl, stearyl,lauryl, isobornyl, cyclohexyl and tert-butylcyclohexyl acrylate ormethacrylate, hydroxyalkyl esters of acrylic acid, methacrylic acid orof another α,β-ethylenically unsaturated carboxylic acid, for example2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropylacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate,2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate or 4-hydroxybutylmethacrylate, corresponding esters of other ethylenically unsaturatedacids having up to 6 carbon atoms in the molecule, for exampleethacrylic acid and crotonic acid, acrylamidomethylpropanesulfonic acid,vinyl-aromatic hydrocarbons, for example styrene, α-alkylstyrene andvinyltoluene, monomers containing amide groups, for example acrylamide,methacrylamide, N-methylolacrylamide and N-methylolmethacrylamide, andmonomers containing nitrile groups, for example acrylonitrile andmethacrylonitrile, or mixtures of the monomers mentioned.

As component (B) a halogen-free copolymer is employed composed of

(b1) from 1 to 99, preferably from 50 to 90% by weight, of propylene,

(b2) from 1 to 99, preferably from 10 to 50% by weight, of at least oneolefin which is copolymerizable with (b1) and contains per molecule fromfive to twenty, preferably from six to eight, carbon atoms, with theexception of isoprene, and

(b3) to 50, preferably from 0 to 25% by weight, of ethylene and/orbutylene,

or of a mixture of such copolymers.

The copolymers employed in accordance with the invention as component(B) have a weight-average molecular weight of from 1000 to 100,000,preferably 3000 to 50,000 (determined by gel permeation chromatographyusing a polypropylene standard) and an iodine number of up to 0.3,preferably from 0.005 to 0.05 mg of I₂/g, and they can have beensubjected to a graft reaction with maleic anhydride.

As component (b2) use is made of at least one olefin which iscopolymerizable with (b1) and contains per molecule from five to twenty,preferably from six to eight, carbon atoms, with the exception ofisoprene. The olefin employed as component (b2) may be unbranched,branched, acyclic or cyclic. Examples of acyclic olefins are pentene,hexene, heptene, octene, nonene and decene. Examples of cyclic olefinsare cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclonone,cyclodecene and norbornene. As component (b2) it is preferred to employpreferably branched or unbranched acylic olefins containing, permolecule, from five to twenty, preferably from six to eight, carbonatoms and only one, preferably α-positioned, olefinically unsaturateddouble bond. Examples of such olefins are 1-pentene, 1-hexene,1-heptene, 1-octene, 1-nonene and 1-decene. As component (b2) it isparticularly preferred to employ 1-hexene, 1-heptene and 1-actene.

In order to prepare the novel water-dilutable binders from 20 to 90% byweight, preferably from 55 to 85% by weight, of the mixture (A) issubjected to free-radical polymerization in the presence of from 9.9 to79.9% by weight, preferably from 15 to 45% by weight, of component (B)and from 0.1 to 10% by weight, preferably from 1 to 7% by weight, ofcomponent (C), and, after neutralization of at least 20% of the carboxylgroups which are present in the resulting polymerization product, thepolymerization product is dispersed in water. The sum of the percentagesby weight of components (A), (B) and (C) is always 100% by weight.

The polymerization of the mixture (A) in the presence of components (B)and (C) can be carried out in bulk, in aqueous emulsion or in an organicsolvent or a mixture of organic solvents. The polymerization ispreferably carried out in an organic solvent or a mixture of organicsolvents, especially in apolar solvents having a boiling range ofbetween 120 to 200, preferably from 135 to 190° C., at polymerizationtemperatures of from 120 to 200° C., preferably from 130 to 160° C.

As component (C) it is possible in principle to employ all knownfree-radical initiators. Those preferably employed are free-radicalinitiators which at the polymerization temperature have a half-life ofbetween 15 and 180 minutes. Examples of free-radical initiators whichcan be employed are: dialkyl peroxides, for example dicumyl peroxide anddi-tertbutyl peroxide, peroxyesters, for example tert-butylperoxybenzoate, tert-butyl peroxyoctanoate, tert-butyl peroxyacetate andtert-butyl peroxyisobutyrate, diacyl peroxides, for example benzoylperoxide and acetyl peroxide, and azo compounds, for exampleazo-bis(isobutyronitrile). As component (C) it is particularly preferredto employ di-tert-butyl peroxide, tert-butyl perethylhexanoate andtert-butyl peracetate.

To neutralize the polymerization product it is preferred to employorganic amines, especially tertiary amines such as, for example,dimethylethanolamine.

Using the novel binders it is possible, by methods which are well knownto the person skilled in the art, to prepare aqueous coating materialswhich can be employed for the priming or one-coat painting of plastics,especially plastics based on polypropylene and/or copolymers ofpropylene and copolymerizable monomers such as ethylene, for example,and which can be used to prepare coating films which adhere very well topretreated and nonpretreated plastics substrates. The novel binders canalso be employed in basecoats for the production of multicoat finishesof the “basecoat-clearcoat” type.

The aqueous coating materials prepared using the novel binders may alsocontain, in addition to the novel binders, other compatible syntheticresins, for example polyacrylate resins, polyester resins andpolyurethane resins (cf. for example DE-A-42 39 695) and crosslinkingagents such as, for example, aminoplastic resins and/or optionallyblocked polyisocyanates. If nonblocked polyisocyanates are employed, itis generally expedient to store the aqueous coating materials as atwo-component system.

The aqueous coating materials prepared using the novel binders can beformulated either with or without pigments and/or fillers. They can alsobe applied in very thin coat thicknesses (from 5 to 10 μm).

The aqueous coating materials prepared using the novel binders generallycontain, in their ready-to-apply state, from 30 to 80, preferably from45 to 70% by weight of water, from 0 to 50, preferably from 0 to 10% byweight of organic solvents, from 6 to 70, preferably from 15 to 45% byweight of the novel binder, from 0 to 40, preferably from 0 to 25% byweight of pigments and/or fillers and from 0 to 10% by weight of otheradditives, for example catalysts, thickeners, leveling agents, etc., thepercentages by weight being based on the overall formulation of thecoating material in the ready-to-apply state (i.e. at spray viscosity,for example).

With the aqueous coating materials prepared using the novel binders itis possible to prime, or to paint in a single coat, plastics such as,for example, ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA,PC, PE, HDPE, LDPE, PETP, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PP-EPDMand UP (abbreviations according to DIN 7728T1), preferably polyolefinssuch as polypropylene and polypropylene-EPDM. The plastics to be paintedmay of course also be polymer blends, modified plastics orfiber-reinforced plastics. The plastics primed with the aqueous coatingmaterials according to this invention may be overpainted using, forexample, one-coat solid-color or metallic systems or two-coatsolid-color or metallic systems of the basecoat-clearcoat type, withoutproblems.

In the text below the invention is illustrated in more detail withreference to working examples. In these examples all parts are by weightunless expressly stated otherwise.

1. PREPARATION OF AN AQUEOUS DISPERSION OF A NOVEL BINDER

300.0 parts of a mixture of aromatic solvents having a boiling range offrom 165° C. to 185° C. (SHELLSOL® A) and 150.0 parts of a randomcopolymer of propylene and hexylene (1-hexene) having a weight-averagemolecular weight of 10,000 g/mol are weighed into a stainless-steelpolymerization vessel with stirrer, reflux condenser, a monomer feed andan initiator feed, and are heated to 115° C. The mixture is stirred atthis temperature for 1 hour. Then a mixture of 36.0 parts of tert-butylperethylhexanoate and 46.5 parts of SHELLSOL® A is added dropwise to thehomogeneous mixture at a constant rate over the course of 5 hours, thetemperature in the reaction mixture being held at 115° C. 30 minutesafter the beginning of the addition of the tert-butyl perethylhexanoatesolution, a mixture of 160.8 parts of butyl methacrylate, 162 parts ofmethyl methacrylate, 168 parts of cyclohexyl methacrylate and 91.8 partsof methacrylic acid are added over the course of 4 hours. After the endof the initiator feed, polymerization is continued for 2 hours more.Then enough solvent is distilled off to give a resin solution having acontent of nonvolatile constituents of 95% by weight. This solution issubsequently diluted with butyl acetate 98/100 to a content ofnonvolatile constituents of 50% by weight, and is cooled to 110° C.Subsequently, 44.9 parts of dimethylethanolamine are added to thissolution and the mixture is stirred for 30 minutes. Then 1834.0 parts ofdeionized water are added with stirring at 80° C. Finally, the organicsolvents are removed by distillation from the aqueous dispersion thusobtained until a residual solvent content of less than 5% by weight hasbeen reached. The aqueous dispersion obtained in this way has a contentof nonvolatile components of 30% by weight (1 h/130° C.), an acid numberof 40 and a pH of 8.2.

2. USE OF THE AQUEOUS DISPERSION PREPARED ACCORDING TO 1. FOR PRIMINGSUBSTRATES OF PP/EPDM

The aqueous binder dispersion prepared according to 1. is diluted withdeionized water to a viscosity of 25 sec (DIN4 cup) and is applied at23° C. and 60% relative atmospheric humidity, using a spray pressure of4-5 bar, to a PP/EPDM test panel (KELTAN TP 0550, DSM) which has beenwiped beforehand with a paper towel impregnated with isopropanol, so asto give a dry film thickness of 5 μm. The film is flashed off at 23° C.for 10 minutes. A solvent-containing metallic basecoat is then appliedunder the abovementioned conditions with a dry film thickness of 15 μm.After a flash-off time of 5 minutes at 23° C., a solvent-containingtwo-component clearcoat is applied under the abovementioned conditionswith a dry film thickness of 40 μm. After a flash-off time lasting 15minutes at 23° C., the entire coating system is baked at an oventemperature of 120° C. for 45 minutes. The coating system prepared inthis way adheres very well to the substrate.

What is claimed is:
 1. An aqueous coating material, comprising at leastone water-dilutable binder resulting from the free-radicalpolymerization of: (A) from 20 to 90% by weight of a mixture ofmonomers, comprising: (a1) from 3 to 50% by weight of a first monomerselected from the group consisting of acrylic acid, methacrylic acid andmixtures thereof, and (a2) from 50 to 97% by weight of an ethylenicallyunsaturated second monomer which is different from said first monomer(a1) or a mixture of such ethylenically unsaturated monomers, whereinthe composition of said mixture of monomers (a1) and (a2) is selectedsuch that polymerization of said mixture of monomers (a1) and (a2) alonegives a polymer which has a glass transition temperature of from 0 to150 degrees C., contains from 0.04 to 1.0 milliequivalents of one ormore of the following functional groups: —COOH, —OH, —NR₃, —CN, —CONH₂,—CO—, —NHCONH—, —OCONH—, —OPO₃H, —OSO₃H, —R—OR—R—, (where R is anorganic radical), and comprises from 0 to 50% by weight of one or morecycloaliphatic groups substituted by at least one alkyl group having 1to 12 carbon atoms and selected from the group consisting ofcyclopentyl, cyclohexyl, perhydronapthyl, perhydroanthracyl,perhydrophenanthryl, adamantyl, isobornyl, bicyclohexyl, bicycloheptyl,bicyclooctyl, bicyclononyl, bicyclodecyl, bicycloundecyl, biciclododecylgroups and mixtures thereof; in the presence of (B) from 9.9 to 79.9% byweight of a halogen-free copolymer composed of: (b1) from 1 to 99% ofpropylene; (b2) from 1 to 99% by weight of at least one olefin which iscopolymerizable with (b1) and which contains per molecule from five totwenty carbon atoms, with the exception of isoprene, and (b3) from 0 to50% by weight, of a member of the group consisting of ethylene butylene,and mixtures thereof, or of a mixture of such copolymers, and (C) from0.1 to 10% by weight of a free-radical initiator or a mixture offree-radical initiators, and, after neutralization of at least 20% ofthe carboxyl groups which are present in the resulting polymerizationproduct, dispersing the polymerization product in water, wherein the sumof the percentages by weight of components (A), (B), and (C) and of (a1)and (a2) and (b1), (b2) and (b3) is, in each case, always 100% byweight.
 2. A process for priming or one-coat painting a plasticsubstrate, comprising providing a plastic substrate, and applying theaqueous coating material of claim 8 to the plastic substrate.
 3. Theprocess of claim 2, wherein the plastic substrate comprisespolypropylene.
 4. An aqueous coating composition, comprising from 30 to80 percent by weight of water, from 6 to 70 percent by weight of awater-dilutable binder, the percentages by weight being based on theoverall formulation of the aqueous coating composition and said bindercomprising the reaction product of the free-radical polymerization of:(A) from 20 to 90% by weight of a mixture of (a1) from 3 to 50% byweight of a monomer selected from the group consisting of acrylic acid,methacrylic acid and mixtures thereof, and (a2) from 50 to 97% by weightof an ethylenically unsaturated monomer which is different from (a1) ora mixture of such ethylenically unsaturated monomers, in the presence of(B) from 9.9 to 79.9% by weight of a halogen-free copolymer composed of(b1) from 1 to 99% of propylene, (b2) from 1 to 99% by weight of atleast one olefin which is copolymerizable with (b1) and contains permolecule from five to twenty, preferably from six to eight, carbonatoms, with the exception of isoprene, and (b3) from 0 to 50% by weight,of a member of the group consisting of ethylene, butylene, and mixturesthereof, or of a mixture of such copolymers, and (C) from 0.1 to 10% byweight of a free-radical initiator or of a mixture of free-radicalinitiators, wherein at least 20% of the carboxyl groups which arepresent in the resulting polymerization product are neutralized and thepolymerization product is dispersed in water to provide a substantiallyhomogenous mixture, the sum of the percentages by weight of components(A), (B) and (C) and of (a1) and (a2) and (b1), (b2) and (b3) are basedon the total weight of the aqueous composition, and the composition ofthe mixture of (a1) and (a2) is selected such that polymerization of themixture of (a1) and (a2) alone gives a polymer which has a glasstransition temperature of from 0 to 150° C., contains from 0.04 to 1.0milliequivalent of one or more of the following functional groups:—COOH, —OH, —NR₃, —CN, —CONH₂, —CO—, —NHCONH—, —OCONH—, OPO₃H, —OSO₃H,—R—O—R—, (where R is an organic radical), and comprises from 0 to 50% byweight of one or more cycloaliphatic groups substituted by at least onealkyl group having 1 to 12 carbon atoms and selected from the groupconsisting of cyclopentyl, cyclohexyl, perhydronaphtyl,perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl,bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl,bicycloundecyl, bicyclododecyl groups and mixtures thereof, and thewater and the water-dilutable binder being mixed so as to provide asubstantially homogenous and stable mixture.
 5. The aqueous coatingmaterial of claim 1, wherein component (A) is employed in a quantity offrom 55 to 85% by weight.
 6. The aqueous coating material of claim 1,wherein component (a1) is employed in a quantity of from 5 to 15% byweight.
 7. The aqueous coating material of claim 1, wherein component(a2) is employed in a quantity of from 85 to 95% by weight.
 8. Theaqueous coating material of claim 1, wherein component (B) is employedin an amount of from 15 to 45% by weight.
 9. The aqueous coatingmaterial of claim 1, wherein from 1 to 7% by weight of component (C) isemployed.
 10. The aqueous coating material of claim 1, whereinpolymerization of the mixture of (a1) and (a2) alone gives a polymercomprising a glass transition temperature of from 10 to 80° C., from 0.1to 1.5 milliequivalent of one or more of the following functionalgroups: —COOH, —CH, —CNH₂, and —R—O—R—, and from 5 to 25% by weight ofcyclohexyl groups or isobornyl groups or of a mixture of these groups.